Laser tissue ablation system

ABSTRACT

Embodiments of the invention are directed to a laser ablation system. In one embodiment, the laser ablation system comprises a shaft, a balloon, a laser fiber and a viewing fiber. The shaft has a proximal end and a distal end. The balloon is attached to the distal end of the shaft, a portion of which is within the balloon. The laser fiber has a distal end comprising a light dispenser that is configured to deliver laser light through the balloon. The viewing fiber is configured to image an interior balloon. In accordance with another embodiment, the laser ablation system comprises a shaft, a balloon and a laser fiber. The shaft has a proximal end and a distal end. The balloon is attached to the distal end of the shaft, which is within the balloon. The balloon includes an inflated state, in which the balloon is shaped to conform to a cavity of a patient. The laser fiber has a distal end comprising light dispenser that is configured to deliver laser light through the balloon.

CROSS-REFERENCE TO RELATED APPLICATION

This Application claims the benefit of U.S. provisional application Ser.No. 61/351,127 filed Jun. 3, 2010.

BACKGROUND OF THE INVENTION

Pelvic conditions include diseases of the uterus, such as uterinefibroids and menorrhagia. Uterine fibroids are non-cancerous tumors ofthe uterus that typically appear on the endometrium layer (i.e., uterinewall) of the uterus. Menorrhagia is a medical condition involvingexcessive and difficult to control bleeding of the endometrial layer ofthe uterus. These conditions have been treated through hysterectomy.However, alternative, less radical approaches are also being used.

One alternative to a hysterectomy is endometrial ablation, which inducesnecrosis of the endometrial layer and a portion of the myometrial layer.These treatments can include freezing and heating the endometrial layer,or cauterizing the endometrial layer using a laser.

SUMMARY

Some embodiments of the invention are directed to a laser ablationsystem. In one embodiment, the laser ablation system comprises a shaft,a balloon, a laser fiber and a viewing fiber. The shaft has a proximalend and a distal end. The balloon is attached to the distal end of theshaft, a portion of which is within the balloon. The laser fiber has adistal end comprising a light dispenser that is configured to deliverlaser light through the balloon. The viewing fiber is configured toimage an interior balloon.

In accordance with another embodiment, the laser ablation systemcomprises a shaft, a balloon and a laser fiber. The shaft has a proximalend and a distal end. The balloon is attached to the distal end of theshaft, which is within the balloon. The balloon includes an inflatedstate, in which the balloon is shaped to conform to a cavity of apatient. The laser fiber has a distal end comprising light dispenserthat is configured to deliver laser light through the balloon.

Additional embodiments are directed to a method a using the laserablation system. In one embodiment, a laser ablation system is providedthat comprises a shaft, a balloon and a laser fiber. The shaft has aproximal end and a distal end. The balloon is attached to the distal endof the shaft, which is within the balloon. The balloon includes aninflated state, in which the balloon is shaped to conform to a uterinecavity of a patient. The laser fiber has a distal end comprising a lightdispenser that is configured to deliver laser light through the balloon.Also in the method, the distal end of the shaft is fed into the uterusof a patient with the balloon in a deflated state. The balloon isinflated with a gas or fluid to the inflated state, in which the balloonsubstantially conforms to the uterine cavity of the patient and engagesthe uterine walls. Laser light is then transmitted through the laserfiber and, the light dispenser and the balloon. The tissue of theuterine walls is ablated responsive to the transmission of the laserlight.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified diagram of a laser tissue ablation system formedin accordance with embodiments of the invention.

FIG. 2 is a cross-sectional view illustrating the attachment of a distalend of a shaft to a balloon, in accordance with an exemplary embodiment.

FIGS. 3 and 4 are simplified diagrams of inflated balloons in accordancewith embodiments of the invention.

FIG. 5 is a cross-sectional view depicting pelvic anatomy of a femalepatient and a distal end of the applicator formed in accordance withembodiments of the invention.

FIG. 6 is an isometric view of a balloon in accordance with embodimentsof the invention.

FIGS. 7 and 8 are side cross-sectional views of a distal end of anapplicator illustrating fluid or gas flow in accordance with embodimentsof the invention.

FIGS. 9 and 10 are side views of light dispensers in accordance withembodiments of the invention.

FIGS. 11 and 12 are side views of the distal end of the applicatorillustrating laser fiber positioning components in accordance withembodiments of the invention.

FIG. 13 is a simplified diagram of the applicator including a handheldunit in accordance with embodiments of the invention.

FIGS. 14-16 respectively show isometric assembled, isometric explodedand magnified isometric views of the applicator with a handheld unitformed in accordance with exemplary embodiments of the invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Embodiments of the present invention are directed to a laser tissueablation system designed to perform tissue ablation and/or other lasertreatments on a patient. While particular embodiments of the inventionwill be described as useful in treating menorrhagia through endometrialablation of the uterine wall of a patient, those skilled in the artunderstand that the system of a present invention may be adapted toperform ablation treatments of other tissue of a patient, such as thatof the anal cavity, the bladder, the vagina, the esophagus, the trachea,the urethra, the ureter, the prostate gland, the kidney, intestinalgrowths or abnormal tissues of the intestine (e.g., hemorrhoids, polyps,etc.) and cancerous tissues.

FIG. 1 is a simplified diagram of a laser tissue ablation system 100formed in accordance with embodiments of the invention. One embodimentof the system 100 includes an applicator 102 that is formed inaccordance with the embodiments described below.

One embodiment of the applicator 102 comprises a shaft 104 having aproximal end 106 and a distal end 108. One embodiment of the shaft 104is formed of a rigid and substantially transparent material, such as,for example, acrylic, PET, silicone, polyurethane, polycarbonate, glassor other suitable material. In one embodiment, the applicator 102includes a balloon 110 that is attached to the shaft 104 proximate thedistal end 108. In one embodiment, the balloon 110 comprises a proximalend 112 and a distal end 114. In one embodiment, the proximal end 112 isattached to the shaft 104 by a sleeve 116 that is formed, for exampleout of Teflon®, which seals an opening of the balloon 110 to the shaft104.

In one embodiment, the distal end 108 of the shaft 104 is attached tothe distal end 114 of the balloon 110. In one embodiment, the shaft 104has a longitudinal axis 117. In one embodiment, the distal end 108 ofthe shaft 104 is secured to the distal end 114 of the balloon 110 alonglongitudinal axis 117. In one embodiment, the longitudinal axis 117 isaligned with a central axis 118 of the balloon 110. In one embodiment,the balloon is symmetric about the longitudinal or central axis 117 wheninflated.

The attachment of the balloon 110 to the shaft 104 can be accomplishedin many different ways. FIG. 2 is a cross-sectional view illustrating anexemplary means of attaching the shaft 104 to the balloon 110 using acap 119. The cap 119 comprises a cylindrical portion 120 that isreceived within a bore 122 of the shaft 104. The distal end 114 of theballoon 110 is captured between the surfaces of the cylindrical portion120 of the cap 119 and the shaft 104. In one embodiment, frictionalresistance prevents the cap 119 from becoming dislodged from the bore122 of the shaft 104. A biocompatible adhesive may also be used tosecure the cap 119 to the distal end 108 of the shaft 104. Othertechniques may also be used to secure the balloon 110 to the distal end108 of the shaft 104.

The balloon 110 has deflated and inflated states. The deflated state 124of the balloon 110 is preferably sufficiently compact to allow thedistal end 108 of the shaft 104 and the attached balloon 110 to beinserted into the desired cavity of the patient, such as the uterus orvagina, to locate the balloon 110 proximate the tissue targeted fortreatment. In one embodiment, the deflated state of the balloon 110 isapproximately 4-6 mm or less in diameter measured radially from thecentral axis 118 of the balloon 110. When in the inflated state, theballoon 110 substantially conforms to the cavity in which it is placed.

In one embodiment, the balloon 110 is be formed of a suitablebiocompatible material. In one embodiment, the balloon 110 is formed ofa distensible material, such as silicone, PET, polyurethane, rubber orother suitable material. The distensible material can stretch responsiveto inflating the balloon 110 from a deflated state 124 (illustrated inphantom in FIG. 1) to an inflated state 126 (solid line), as shown inFIG. 1, due to an increase in the pressure of the interior 128 of theballoon 110. The distensible material allows the balloon 110 to furtherconform to the cavity of the patient in which it is placed in responseto pressure exerted on the balloon 110 from the walls of the cavity.

In accordance with another embodiment, the balloon 110 is formed ofminimally distensible material, such as polyurethane, or other suitablematerial.

In one embodiment, the balloon 110 includes an Inhibizone coating, suchas that described in U.S. Pat. No. 5,756,145, which is incorporatedherein by reference in its entirety.

FIGS. 3 and 4 are simplified diagrams of the balloon 110 in the inflatedstate 126, in accordance with embodiments of the invention. In oneembodiment, the inflated state 126 of the balloon 110 has a cylindricalshape with a rounded distal end 114, as illustrated in FIGS. 1 and 3.

In accordance with another embodiment, the inflated state 126 of theballoon 110 has a predefined non-cylindrical or spherical shape whenviewed in a plane aligned with the central axis of the balloon 117.Rather, the inflated state 126 of the balloon has a shape that conformsto the interior cavity of the patient where the tissue targeted forablation is located. One exemplary embodiment is illustrated in thesimplified side view of FIG. 4, in which the inflated state 126 of theballoon 110 is shaped to conform to the uterus of a patient. The balloon110 can take on other cavity-conforming shapes, such as the vagina, theanal cavity, esophagus, trachea, bladder and any other cavity within thebody.

When the balloon 110 is formed of substantially non-distensiblematerial, the predefined inflated shape 126 of the balloon 110 willdrive the tissue of the cavity into conformity with the balloon 110.When the balloon 110 is formed distensible material, the inflated state126 of the balloon will generally conform to the cavity of the patient.As a result, the balloon 110 may only minimally deflect the walls of thecavity when the balloon is inflated. Further, the balloon 110 will alsodeform in response to engagement with the walls of the cavity.

In one embodiment, the pre-defined shape of the inflated state 126 ofthe balloon prevents the balloon from applying significant pressures tothe walls of the cavity of the patient. In one embodiment, the balloon110 applies less than 10 psi to the walls of the cavity of the patientin which it is inflated. Thus, the balloon 110 having a pre-definedinflated shape can significantly reduce the pressure on the walls of thecavity of the patient in which the balloon 110 is inflated. This canreduce patient intraoperative and post operative pain.

FIG. 5 is a cross-sectional view of a female patient depicting thevagina 132, the cervix 134 and the uterus 136. The distal end 108 of theshaft 104 and a balloon 110 are inserted through the cervix 134 and intothe uterus 136 when the balloon 110 is in the deflated state 124. Theballoon 110 is then expanded to the inflated state 126 (shown), in whichthe balloon 110 substantially conforms to the shape of the uterine wall138. The balloon 110 preferably engages the uterine wall 138 whileapplying minimal pressure. In one embodiment, the balloon 110 appliesless than 10 psi to the uterine wall 138 when in the inflated state 126.

In one embodiment, the balloon 110 includes markings 139, as shown inFIG. 6. The markings 139 can be viewed from within the interior 128 todetermine whether the balloon 110 is properly inflated and/or positionedwithin the cavity of the patient. In one embodiment, the markings 139comprise one or more visible lines extending longitudinally (i.e., lines139A), and/or circumferentially (i.e., lines 139B) around the balloon110. In one embodiment, the markings 139 comprise a grid pattern.

In one embodiment, the balloon 110 seals the distal end 108 of the shaft104. A seal 142, such as an o-ring, or other suitable seal, seals theproximal end 106 of the shaft 104. In one embodiment, the balloon 110 isinflated using a simple saline solution.

In one embodiment, the balloon 110 may be inflated with fluid or gas. Inone embodiment, the shaft 104 includes a port 140, as shown in FIG. 1,through which the fluid or gas may be received. In one embodiment, thesystem 100 comprises a pump 144 that drives a fluid or gas from a supply146 through the port 140 and into the interior 128 of the balloon 110 todrive the balloon 110 to its inflated state 126. The pump 144 can takeon many different forms. In one embodiment, the supply 146 is in theform of a pressurized gas, in which case, the pump 144 may represent avalve that controls the flow of the gas from the supply 146. Inaccordance with another embodiment, the pump 144 drives a fluid from thesupply 146 through the port 140 and into the interior 128 of the balloon110 to inflate the balloon 110. Embodiments of the pump 144 include asyringe, a diaphragm pump, gear pump, or other suitable pump.

In one embodiment, gas or fluid enters the shaft 104 through the port140, shown in FIG. 1. In one embodiment, the shaft 104 includes a fluidpath 149 that fluidically couples the port 140 to openings 148 in theshaft 104 to the interior 128 of the balloon 110, as shown in FIG. 7.The gas or fluid entering the port 140 flows through the fluid path 149,through the openings 148 and into the interior 128 of the balloon 110 asshown in FIGS. 1 and 7. In accordance with one embodiment, the fluid orgas within the interior cavity 128 of the balloon 110 may be dischargedback through the openings 148 of the shaft 104 and out the port 140.Alternatively, as shown in FIG. 7, the fluid or gas within the interiorcavity 128 of the balloon 110 may be discharged through one or moreopenings 150 to a fluid path 152 that is connected to a dedicated drainport 154 (FIG. 1).

In accordance with one embodiment, the balloon 110 comprises an interiorballoon 110A and an exterior balloon 110B, as shown in the simplifiedside-cross sectional view of FIG. 8. In accordance with one embodiment,either the interior balloon 110A or the exterior balloon 110B is formedof a non-distensible material, while the other balloon 110A or 110B isformed of a distensible material. In one embodiment, the interiorballoon 110A is formed of a substantially non-distensible or minimallydistensible material and has a predefined shaped in accordance withembodiments described above. In accordance with one embodiment, abiocompatible lubricant is located between the interior balloon 110A andthe exterior balloon 110B.

In accordance with one embodiment, the fluid or gas driven through theport 140 is fed between the interior balloon 110A and the exteriorballoon 110B, as represented by the arrows in FIG. 8. In one embodiment,the fluid is discharged through the fluid path 152 and out the drainport 154. The flow of fluid between the balloons 110A and 110B can beused to control the temperature of the tissue that is in contact withthe balloon 110B.

One embodiment of the system 100 includes a conventional laser source160 that can be attached to a waveguide 162, such as an optical fiber(hereinafter “laser fiber”), that can be received within the shaft 104.The laser source 160 can be a conventional laser generating system. Inaccordance with one embodiment, the laser source 160 is configured togenerate laser light or a laser 164 having a desired wavelength forperforming surgical procedures, such as tissue ablation.

In one embodiment, the laser source 160 is configured to produce anNd:YAG laser operating at approximately 532 nanometers or 1064 nanometerwavelengths. The laser source 160 may be a solid state laser based on apotassium-titanyl-phosphate (KTP) crystal, a lithium triborate (LBO)laser, a beta barium borate (BBO), a holmium laser and a thulium laser,or other type of laser source used to perform tissue ablation or otherlaser treatment. Exemplary laser sources 160 are described in U.S. Pat.No. 6,986,764 (Davenport), which is incorporated herein by reference inits entirety.

The laser 164 generated by the laser source 160 travels through thelaser fiber 162 and is discharged through a light dispenser 166 at adistal end 168. In one embodiment, the dispensed laser light 164 istransmitted through the shaft 104 and the balloon 110 and onto thetargeted tissue of the patient, such as the uterine wall 138 shown inFIG. 5.

The light dispenser 166 is configured to discharge the laser light 164in a desired manner, such as along the axial and/or radial directions ofthe laser fiber 162, to one side of the laser fiber 162, in a diffusepattern around the dispenser 166, and/or other desired manner. Exemplarylight dispensers 166, such as side-fire optical caps, are disclosed inU.S. Pat. No. 5,428,699 (Pon), U.S. Pat. No. 5,269,777 (Doiron et al.),U.S. Pat. No. 5,530,780 (Ohsawa), and U.S. Pat. No. 5,807,390 (Fuller etal.).

In one embodiment, the light dispenser 166 comprises an etched section170 of the laser fiber 162, as shown in FIG. 9, to dispense the laserlight 164 in a diffuse pattern. In one embodiment, portions of theetched section 170 are tapered to direct the diffused laser light in adesired manner, such as axially. The etching can be made using anappropriate laser, such as a CO₂ laser, to roughen the exterior surfaceof the laser fiber 162. In one embodiment, a cap 172 encloses thedispenser 166, as shown in FIG. 9.

If the laser light 164 is output from the dispenser 166 in an evendispersion pattern, the targeted tissue located farther away willreceive less laser light energy than the targeted tissue located closerto the dispenser 166. In one embodiment, the etching pattern of thesection 170 is customized to include portions that transmit more lightenergy than other portions to customize the laser energy dispersionpattern output from the dispenser 166. That is, the etched section 170may comprise different patterns in different portions of the section 170to provide different levels of laser light transmission through thedifferent portions of the section 170. This allows the targeted tissueto receive similar intensity levels of the dispensed laser light 164even though the targeted tissue is not located a uniform distance fromthe dispenser 166.

In accordance with one embodiment, light transmission through theballoon 110 is non-uniform. In one embodiment, light transmissionthrough the balloon varies along the central axis 118 of the balloon110. That is, portions of the balloon 110 at different locations alongthe axis 118 (e.g., portions in a plane that is perpendicular to theaxis 118) have a degree of laser transparency that is different fromother portions of the balloon along the axis 118. This allows for thecontrol of the transmission of the laser light 164 through the balloon110 and, therefore, the amount of laser energy that is delivered to thetargeted tissue.

In one embodiment, the material forming the balloon provides apredefined pattern of laser transparency variation along the axis 118,such as, for example, by varying a thickness of the balloon 110. In oneembodiment, printing or a coating of material on of the balloon 110,such as on the interior wall 190 (FIG. 1), defines the desired patternof laser transparency though the balloon 110. In one embodiment, theprinting or coating defines the pattern of laser transparency byapplying the printing or coating to select portions of the balloon 110,applying the printing or coating in a varying pattern on the balloon110, and/or applying the printing or coating in a varying thickness onthe balloon 110. Embodiments of the coating may comprise titaniumdioxide (TiO₂), Tampapur Ink, and/or parylene. In one embodiment, thecoated or printed material is reflective.

FIG. 10 illustrates a simplified diagram of a light dispenser 166 inaccordance with another embodiment of the invention. In accordance withthis embodiment, the light dispenser 166 comprises a plurality of glassbeads 174 within the balloon 110. The laser light is discharged throughthe distal end 168 of the laser fiber 162 and interacts with the glassbeads 174 to disperse the laser light 164 around the surface of theballoon 110.

In one embodiment, the distal end 108 of the shaft 104 is configured totransmit the laser light 164 discharged through the dispenser 166 of thelaser fiber 162 at varying degrees of efficiency. That is, sections ofthe shaft 104 are configured to be more transparent to the laser light164 than other sections of the shaft 104. This pattern of lasertransparency of the shaft may be formed in various ways. In oneembodiment, the interior or exterior wall of the shaft 104 is coated asdescribed above with regard to the balloon 110. Alternatively, thepattern may be formed on the shaft 104 by etching the pattern on theshaft 104, applying a particulate to the shaft 104 that blocks the laserlight 164, tinting the shaft 104, or other suitable technique forcreating the desired pattern of laser transparency through the shaft104. As discussed above with regard to the dispenser 166 illustrated inFIG. 9, the control of the transmission of the laser light 164 throughthe shaft 104 provides control over the amount of laser energy that isdelivered to the targeted tissue.

One embodiment of the system 100 includes one or more laser fiberpositioning components 180 represented schematically in FIG. 1. In oneembodiment, the positioning components 180 are configured to move thelaser fiber 162 axially along the longitudinal axis of the laser fiber,as indicated by arrow 176 in FIG. 1, relative to the shaft 104 and/orthe balloon 110. This axial movement of the distal end 168 laser fiber162 causes the laser fiber 162 to generally move along the longitudinalaxis 117 of the shaft 104 and along the central axis 118 of the balloon110 relative to the balloon 110 and the shaft 104. In accordance withone embodiment, the distal end 168 of the laser fiber 162 may be movedaxially by the one or more components 180 to withdraw the distal end 168and the dispenser 166 of the laser fiber 162 from within the interior128 of the balloon 110. The components 180 may also move the distal end168 and the dispenser 166 of the laser fiber 162 into the interior 128of the balloon 110. Thus, the dispenser 166 of the laser fiber 162 maybe positioned in the desired location relative to the balloon 110 andthe shaft 104 using the one or more laser fiber positioning components180.

In accordance with another embodiment, the laser fiber positioningcomponents 180 are configured to rotate the laser fiber 162 about itslongitudinal axis and, thus, rotate (i.e., move angularly) the dispenser166 about the longitudinal axis. This may be useful when the dispenser166 is configured to output the laser light 164 radially out a side ofthe dispenser 166 over a range of less than 360 degrees. With such aconfiguration, the dispenser 166 can be made to output the laser light164 to the tissue surrounding the dispenser 166 by rotating thedispenser 360 degrees using the positioning components 180.

In accordance with one embodiment, the one or more positioningcomponents 180 are configured to move the distal end 168 of the laserfiber 162 in an arc relative to the balloon 110. FIGS. 11 and 12illustrate exemplary components 180 for moving the distal end of thelaser fiber 162 in an arc. In one embodiment, the components 180comprise at least two balloons 182 and 184 that may be inflated anddeflated through the pumping of a gas or fluid through suitable conduit(not shown) coupled to the balloons 182 and 184. In one embodiment, thedistal end 168 of the laser fiber 162 is not covered by the shaft 104.Movement of the distal end 168 of the laser fiber 162 along an arc inthe direction indicated by arrow 186 is accomplished by deflating theballoon 184 and inflating the balloon 182, as shown in FIG. 11.Likewise, the distal end 168 of the laser fiber 162 may be moved in anarc in the direction indicated by arrow 188 by deflating the balloon 182and inflating the balloon 184, as shown in FIG. 12. Additional balloonsmay be used in a similar manner to displace the distal end 168 of thelaser fiber 162 along an arc in the desired direction.

One embodiment of the system 100 includes a viewing system 200 that isconfigured to provide the physician with a view from the interior 128 ofthe balloon 110. One embodiment of the viewing system 200 comprises aviewing fiber 202 that is received within the shaft 104, as shown inFIG. 1. In one embodiment, the distal end 204 comprises an imagingcomponent 206, such as a charge coupled device (CCD) that is configuredto image the interior 128 of the balloon 110 through the shaft 104. Theimaging component 206 may be a conventional device that includes thenecessary electronics to deliver the image data down the viewing fiber202 to a suitable viewing console 208 through one or more wires (notshown). A capsule or other protective means can protect the imagingcomponent 206 from the environment within the interior 128 of theballoon 110.

In one embodiment, the viewing system 200 includes one or more viewingfiber positioning components 210 that are configured to adjust theposition and/or orientation of the imaging component 206 to image thedesired portion of the balloon 110 or the targeted tissue of thepatient. In one embodiment, the positioning components 210 areconfigured to move the viewing fiber 202 axially along the longitudinalaxis of the viewing fiber, as indicated by arrow 211 in FIG. 1 relativeto the shaft 104 and/or the balloon 110. Accordingly, the distal end 204of the viewing fiber 202 may be moved axially by the one or morecomponents 210 to withdraw the imaging component 206 from within theinterior 128 of the balloon 110. The imaging component 206 can be movedfrom this withdrawn position into the interior 128 of the balloon 110and positioned in a desired location relative to the balloon 110 and theshaft 104. In accordance with another embodiment, the viewing fiberpositioning components 210 are configured to rotate the viewing fiber202 about its longitudinal axis and, thus, rotate the imaging component206 about the longitudinal axis of the viewing fiber 202. This allowsthe imaging component 206 to image a full 360° around the longitudinalaxis of the viewing fiber 202.

Exemplary positioning components for the laser fiber 162 and thecomponents 210 for the viewing fiber 202 include components thatfacilitate the hand feeding of the fibers 162 and 202, and componentsthat drive the feeding of the laser fiber 162 and the viewing fiber 202,such as rollers that are rotated by hand or driven by a motor, or othersuitable mechanism for feeding the laser fiber 162 and the viewing fiber202 in their axial directions. In one embodiment, the components 180 and210 are configured to rotate the laser fiber 162 and the viewing fiber202, respectively, and include components that facilitate the rotationof the fibers by hand, mechanisms that are driven by hand or by a motorthat engage the fibers and rotate the fibers about their longitudinalaxis, or other components that can be used to rotate the fibers.

Another embodiment of the system 100 includes one or more sensors 212(FIG. 1) that are configured to sense a parameter of the system 100and/or the patient. One embodiment of the sensors includes a temperaturesensor, such as a thermal couple, that is configured to sense thetemperature of the balloon 110 and/or the tissue of the patient. Inaccordance with one embodiment, when the balloon 110 comprises andinternal balloon 110A and an external balloon 110B (FIG. 8), thetemperature sensor is located between the balloons 110A and 110B. Inaccordance with another embodiment, the sensors 212 include a pressuresensor configured to detect a pressure of the interior 128 of theballoon 110. In one embodiment, the system 100 includes a sensor in theform of a flow meter 213 (FIG. 1) that is configured to detect the flowrate of fluid driven by the pump 144. Signals from the one or moresensors 212 are fed via wires or other conventional means to acontroller 214 that can use the information received from the sensors212 to control components of the system 100, such as the pump 144.

One embodiment of the applicator 102 comprises a handheld unit 220, anexemplary embodiment of which is illustrated in FIG. 13. The handheldunit 220 is generally configured to support components of the applicator102 described above. In one embodiment, the unit 220 is configured tosupport the proximal end 106 of the shaft 104. In one embodiment, theunit 220 is configured to support the laser fiber 162. In accordancewith other embodiments, the handheld unit 220 is configured to supportthe viewing fiber 202, the one or more laser fiber positioningcomponents 180 and/or the one or more viewing fiber positioningcomponents 210 described above. In accordance with another embodiment,the handheld unit 220 is configured to receive tubing 250 used to pumpfluid or gas through the shaft 104 and into the balloon 110.

In one embodiment, the handheld unit 220 allows the laser fiber 162 topass through the body of the unit 220 for attachment to the laser system160. Similarly, the handheld unit 220 allows for the viewing fiber 202to pass through the body of the unit 220 for coupling to the viewingsystem 208.

In one embodiment, the handheld unit 220 supports a laser actuator 222that is configured to trigger the laser system 160 to deliver laserenergy down the laser fiber 162 to the distal end 168. Embodiments ofthe laser actuator 222 include a button, a finger trigger, or othersuitable mechanism. One embodiment of the laser actuator 222 that is notsupported by the handheld unit 220 is a foot-activated switch.

FIGS. 14-16 respectively show isometric assembled, isometric explodedand magnified isometric views of the applicator 102 with a handheld unit220 formed in accordance with exemplary embodiments of the invention. Inone embodiment, the handheld unit 220 comprises a pistol grip 230 and asupport member 232 that extends transversely to the pistol grip 230. Inone embodiment, the support 232 comprises a hinged cover 234 having aclosed position (FIG. 14) and an opened position (FIG. 15). A bore 236is formed in the support 232 and/or the cover 234 and is sized toreceive the shaft 104, as shown in FIG. 16. In one embodiment, the shaft104 is securely held within the bore 236 when the cover 234 is in theclosed position such that inadvertent movement of the shaft 104 in thelongitudinal direction during normal handling of the applicator 102 isprevented. In one embodiment, the support 232 and/or the cover 234includes a shoulder portion 238 at a proximal end 240 of the bore 236that prevents the shaft 104 from sliding toward the rear 242 of thesupport 232 along the longitudinal axis.

In one embodiment, the support 232 and/or the cover 234 comprise achannel 244 that is configured to receive the laser fiber 162, as bestshown in FIG. 16. The channel 244 extends to the shoulder portion 238where it receives the laser fiber 162 where it exits the shaft 104. Thechannel 244 extends from the shoulder 238 out the rear end of thesupport 232 where it can be coupled to the laser system 160 in aconventional manner.

Another embodiment of the handheld unit 220 comprises a channel 246formed in the support 232 and/or the cover 234, as best shown in FIG.16. The channel 246 extends from the shoulder portion 238 out the rearend 242 of the support 232. The channel 246 is configured to receive theviewing fiber 220 as it exits the proximal end 106 of the shaft 104 andallows the viewing fiber 202 to extend out the rear end 242 of thesupport member 232 where it can be connected to the viewing system 208.

In one embodiment, the handheld unit 220 includes a channel 248configured to receive conduit 250 that is coupled to the fluid inputport 140, as shown in FIG. 16. In one embodiment, the channel 248extends through the support 232 and the pistol grip 230. The exposed endof the conduit 250 may be coupled to the flow meter 213 or pump 144using conventional means.

As discussed above, one embodiment of the handheld unit 220 includes theone or more laser fiber positioning components 180. In one embodiment,the laser fiber positioning components 180 comprise a thumb wheel 252that is coupled to a roller 252 through a gear, axle, or other suitablearrangement, as shown in FIG. 15. The roller 252 engages the laser fiber162 through a slot 256 in the support 232, as shown in FIG. 16. Oneembodiment of the roller 252 comprises an exterior surface thatcomprises rubber or other suitable material that provides sufficientfrictional resistance with the exterior of the laser fiber 162 to gripthe laser fiber 162 and inhibit sliding contact between the roller 254and the laser fiber 162. Rotation of the thumb wheel 252 rotates theroller 254, which drives the longitudinal movement of the laser fiber162 in either the forward or rearward direction relative to the handheldunit 220 and the shaft 104. Thus, one may move the distal end 168 of thelaser fiber 162 relative to the balloon 110 to position the distal end168 as desired.

One embodiment of the one or more viewing fiber positioning components210 includes a thumb wheel 258 and a roller 260 that operate similarlyto the thumb wheel 252 and roller 254 described above to move theviewing fiber 202 in the longitudinal direction relative to the handheldunit 220, the shaft 104 and the balloon 110. The thumb wheel 258 iscoupled to the roller 260 through a suitable arrangement, such as agear. The roller 260 is exposed to engage the viewing fiber 202 througha slot 262 in the support 232. The roller 260 comprises an exteriorsurface that is formed of a material (e.g., rubber) that generatessufficient frictional resistance with the viewing fiber 202 to inhibitsliding contact between the roller 260 and the viewing fiber 202 as theroller 260 is rotated. Rotation of the thumb wheel 258 causes the roller260 to rotate, which drives the viewing fiber in the longitudinaldirection relative to the handheld unit 220, the shaft 104 and theballoon 110. Thus, the longitudinal position of the distal end 204 ofthe viewing fiber 202 can be positioned as desired relative to theballoon 110 using the thumb wheel 258.

Another embodiment of the handheld unit 220 comprises one or moreviewing fiber positioning components 210 that are configured to rotatethe viewing fiber 202 about its longitudinal axis. One embodiment of thecomponents 210 comprise a rotatable member 264, such as a thumb wheel,and a roller 266. The rotatable member 264 is coupled to the roller 266through an axle, gear, or other suitable arrangement, such that rotationof the member 264 causes the roller 266 to rotate. In one embodiment,the axes of rotation of the member 264 and the roller 266 are parallelto the longitudinal axis of the viewing fiber 202 and the channel 246.The roller 266 engages the viewing fiber 202 through a slot 268. Theexterior surface of the roller 266 is formed of a material (e.g.,rubber) that produces sufficient frictional resistance with the viewingfiber 202 to inhibit sliding contact with the viewing fiber 202 as theroller 266 rotates. The rotation of the member 264 causes the roller 266to rotate, which drives the rotation of the viewing fiber 202 about itslongitudinal axis. This allows the distal end 204 of the viewing fiber202 to be rotated as desired within the balloon 110. One embodiment ofthe one or more laser fiber positioning components 180 includescomponents that are similar to the rotatable member 264 and the roller266 that can be used to rotate the laser fiber 162 about itslongitudinal axis.

In one embodiment, the handheld unit 220 includes the laser actuator 222in the form of a trigger 270 that is mounted to the support 232. In oneembodiment, actuation of the trigger 270 directs the laser system 160 totransmit laser light through the laser fiber 162 for discharge throughthe dispenser 166.

In one embodiment, the shaft 104, the balloon 110, the laser fiber 162,the viewing fiber 202, the tubing 250, and/or the port 140 form adisposable group of components. In one embodiment, one or more of thesecomponents are provided as a kit in sterilized packaging. In oneembodiment, one or more of these components come pre-assembled. Forinstance, a disposable assembly may comprise the shaft 104, the balloon110, the laser fiber 162 and the tubing, as shown in FIG. 15, that isready for installation within the handheld unit 220. One or more of theother components described above, such as the seal 142, may also beincluded the disposable assembly.

Additional embodiments of the invention include methods of ablatingtissue of a patient, or performing another laser treatment, using thesystem 100. In one embodiment of the method, the system 100 formed inaccordance with one or more embodiments described above is provided andthe system is prepared for the ablation operation. This may involve theproviding of the disposable assembly described above in, for example,sterilized packaging. The disposable assembly is then installed in thehandheld unit 202.

In one embodiment, the laser fiber 162 is connected to the laser system160. In one embodiment, the viewing fiber 202 (if present) is connectedto the viewing console 208. In one embodiment, the tubing 250 isfluidically coupled to the pump 144. In one embodiment, connections aremade between the one or more sensors 212 and the controller 214.

In one embodiment, a coating, such as an adjuvant, is applied to theexterior surface of the balloon 110, which is placed in contact with thetarget tissue when the balloon 110 is inflated within the cavity of thepatient. The adjuvant is designed to enhance laser tissue ablation byabsorbing the wavelength of laser light that will be applied to thetissue. Embodiments of the coating are described in U.S. patentapplication Ser. No. 12/468,668 filed May 19, 2009 entitled “ADJUVANTENHANCED ABLATION,” which is incorporated herein by reference in itsentirety.

In one embodiment, the balloon 110 is placed in the deflated state 124and the distal end 108 of the shaft 104 is fed into the cavity of thepatent, such as the uterus, where the target tissue is located. In oneembodiment, the cavity is visually inspected using the viewing fiber202.

In one embodiment, the balloon 110 is inflated within the cavity bypumping either fluid or gas through the tubing 250 and the port 140,such as using the pump 144. In one embodiment, the inflated state 126 ofthe balloon engages the interior wall of the cavity, such as illustratedin FIG. 5.

In one embodiment, the cavity and the inflated balloon 110 are inspectedusing the viewing fiber 202. This involves moving the distal end 204 ofthe viewing fiber 202 axially and/or angularly using the one or moreviewing fiber positioning components 210.

In one embodiment, the markings 139 on the balloon are imaged or viewedusing the viewing fiber 202. The markings indicate whether the balloon110 is properly inflated and/or positioned within the cavity of thepatient. In one embodiment, the balloon 110 is deflated, repositionedand inflated again until the markings 139 indicate that the balloon 110is fully inflated and/or in the desired position within the cavity.

In one embodiment, the laser fiber 162 is positioned as desired relativeto the shaft 104 and the balloon 110 using the one or more laser fiberpositioning components 180. This may involve moving the distal end 168axially, angularly, or along an arc.

In one embodiment, the laser system 160 is activated to transmit laserlight 164 through the laser fiber 162 and out the dispenser 166 toablate the targeted tissue. In one embodiment, this activation of thelaser system is responsive to the actuation of the laser actuator 222.In one embodiment, the targeted tissues are inspected using the viewingfiber 202.

In one embodiment, the dispenser 166, the distal end 108 of the shaft104, and/or the balloon 110 are configured to provide substantiallyuniform transmission of the laser light 164.

In one embodiment, the dispenser 166, the distal end 108 of the shaft104, and/or the balloon 110 are configured to provide non-uniformtransmission of the laser light to control the exposure of the targettissue to the laser light. In one embodiment, a coating is applied tothe shaft 104 and/or the interior of the balloon 110 to control thetransmission of the laser light therethrough.

In one embodiment, the distal end 168 of the laser fiber 162 is movedalong an arc and/or axially to another position relative to the shaft104 and the balloon 110 to target other tissue within the cavity of thepatient.

In one embodiment, a flow of fluid or gas is circulated through theballoon 110. In one embodiment, the flow of fluid or gas is regulatedresponsive to a temperature signal from a temperature sensor 212.

Following the completion of the ablation treatment, the balloon 110 isreturned to its deflated state 124 and the balloon 110, the shaft 104,the laser fiber 162 and other components of the system (e.g., theviewing fiber 202) are removed from the cavity. The disposablecomponents can then be detached from the laser system 160, the pump 144and the viewing console 208, removed from the applicator 102 anddiscarded.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

What is claimed is:
 1. A laser ablation system comprising: a shafthaving a proximal end and a distal end; and a first balloon attached tothe distal end of the shaft, wherein the distal end of the shaft iswithin the first balloon; a second balloon within the first balloon,wherein the second balloon is formed of a material that is lessdistensible than a material forming the first balloon; a laser fiberhaving a distal end comprising a light dispenser configured to deliverlaser light through the first and second balloons; and a viewing fiberconfigured to image an interior of the second balloon.
 2. The system ofclaim 1, wherein the first balloon has an inflated shape thatsubstantially conforms to a cavity selected from the group consisting ofa uterine cavity, an anal cavity, an esophagus, a trachea, a vagina, abladder, a urethra and a ureter.
 3. The system of claim 1, wherein thefirst balloon substantially conforms to a uterine cavity of a patient.4. The system of claim 1, wherein transparency of the first balloon tolaser light is non-uniform.
 5. The system of claim 4, wherein: the shafthas a longitudinal axis; and the transparency of the first balloon tolaser light varies along the longitudinal axis.
 6. The system of claim1, wherein the shaft comprises: first and second openings at the distalend; first and second ports at the proximal end; a first fluid pathwayconnecting the first port to the first opening; and a second fluidpathway connecting the second port to the second opening.
 7. The systemof claim 6, further comprising a fluid or gas supply fluidically coupledto the first port.
 8. The system of claim 1, further comprising a lasersystem coupled to a proximal end of the laser fiber and configured totransmit laser light through the laser fiber and the light dispenser. 9.The system of claim 1, further comprising a handheld unit configured tosupport the proximal end of the shaft, the laser fiber and the viewingfiber.
 10. The system of claim 9, wherein the handheld unit comprisesone or more laser fiber positioning components configured to rotate thelaser fiber about a longitudinal axis of the laser fiber relative to theshaft, move the laser fiber along the longitudinal axis of the laserfiber relative to the shaft, and/or move the distal end of the laserfiber along an arc relative to the first balloon.
 11. The system ofclaim 10, wherein the handheld unit comprises one or more viewing fiberpositioning components configured to rotate the viewing fiber about alongitudinal axis of the viewing fiber relative to the shaft, and/ormove the viewing fiber along the longitudinal axis of the viewing fiberrelative to the shaft.
 12. The system of claim 1, wherein the firstballoon is formed of a distensible material.